In the beverage serving industry, beverages are commonly dispensed from a tap that is connected to a bulk receptacle (eg. a keg) through beverage lines or conduits.
This is a common arrangement, for example, in serving beer at public bars.
In order to serve the beverage at an appropriate temperature, the beverage lines or conduits can be chilled or cooled. In some instances, this involves passing the beverage lines through a cold bath. However, the transition of the lines from the bath to the tap allows the beverage to absorb heat from the surrounding atmosphere which may lead to the beverage being served warmer than desired.
To counter this issue heat exchange conduits are used to extract heat from the beverage conduits. The heat exchange lines run in parallel with the beverage lines, and contain a cooled fluid. Thus the temperature of the heat exchange conduit is, at least initially, lower than that of the beverage lines to enable heat to be extracted from the latter to the former.
However, since it is more energy efficient to maintain the temperature of a volume of fluid in a bath rather than in individual conduits, the heat exchange lines usually connect to a cooling or refrigeration system that includes a tank or bath of cooled fluid. The cooled fluid is then metered into the heat exchange lines as needs be.
Such tanks are stored in coolrooms for protection from ambient heat. Therefore, such tanks occupy space in the coolroom that might otherwise be used to chill beverages and/or food. Since positioning tanks outside the coolroom causes the fluid to absorb heat from the atmosphere through the body of the tank, positioning such tanks outside of coolrooms is considered undesirable.
In addition, the fluid in the tank is cooled using a refrigerant circuit. Since the refrigerant circuit includes a condenser, and since the condenser is designed to give off heat, the condenser must be separated from the tank and placed outside the coolroom (i.e. the system is a “split” system). Such a system is undesirable since space must then be dedicated to the condenser alone, and repositioning the split system is inconvenient.
A further drawback inherent in such systems is that the beverage lines are intentionally cold, which makes them difficult to clean. Detergents that are active at lower temperatures have been developed, however, these are not always effective.
Poor cleaning of the beverage lines leads to a build up of biofilm—an organic film that forms on the inside of the beverage lines and can corrupt the taste of the beverage or make it unpalatable to drink.
A common technique of cleaning beverage lines is to raise the temperature of cleaning solution in the beverage lines by switching off the beverage cooling system and allowing it to absorb atmospheric heat for an extended period of time so that the fluid warms up to just below ambient temperature, which then allows the cleaning solution to warm up. This has the effect of making biofilm more easily dislodged, enabling the biofilm to be flushed from the lines during the beverage lines' cleaning process.
A drawback of such a method of cleaning is that it is time consuming to wait for the temperature to rise sufficiently to ensure proper cleaning, with a consequent reduction in the time during which beverages can be dispensed for consumption. Also, since the entire body of fluid increases in temperature this leads to a significant expenditure of time and energy when cooling the fluid after cleaning.
A system or circuit is therefore desired that improves the efficiency of the cleaning process and/or improves the efficiency of cooling beverage.